Formal/Literary:
* Le chagrin d'amour: This is the most literal and common translation, meaning "love sorrow".
* La douleur amoureuse: This translates as "love pain" and is another formal option.
Informal/colloquial:
* Le cœur brisé: This literally means "broken heart" and is a more common way to say "heartbreak" in everyday speech.
* La déception amoureuse: This translates as "love disappointment" and is another informal option.
Other options:
* La souffrance amoureuse: "Love suffering"
* La peine d'amour: "Love grief"
The best translation depends on the context of your sentence and the specific emotion you want to express.